Power management for a handheld measurement system

Abstract

A method and system suitable for managing the power consumption of a handheld measurement system that combines a handheld computer, measurement sled, and sensors is provided. The handheld computer performs timing operations for sensor warm up and also shutting down the sensor power during a period of user inactivity after no measurements are being acquired. Additionally, the sled's firmware, implements simple sensor power on and off commands in response to the user.

1. A method for managing power consumption by a user in a handheld measurement system having a handheld computer connected to a measurement sled and one or more sensors, comprising:
 retrieving user commands by performing timing operations by the handheld computer for determining when sensor warm up is required and for shutting down sensor power during a period of user inactivity when no measurements are being acquired, and 
 determining if a command has been sent from the handheld computer to the sled wherein if a command has been sent then turning-on the sled's central processing unit and performing the command and if no command has been received placing the sled's central processing unit in a low power mode. 
 
   
   
     2. The method for managing power consumption by the handheld measurement system according to  claim 1 , further comprising: performing sensor power on and off commands by the sled in response to user commands. 
   
   
     3. The method for managing power consumption by the handheld measurement system according to  claim 2 , further comprising: determining if the command sent from the handheld computer turns on one or more sensors and if a command has been sent then turning-on the one or more sensors and if no command has been sent then turning-off the one or more sensors and placing the sled's central processing unit in a low power mode. 
   
   
     4. The method for managing power consumption by the handheld measurement system according to  claim 3 , further comprising: determining if a sled sensor read command has been received when the user inactivity timeout period has not occurred wherein if the sensor read command has been received then refreshing the user inactivity timeout and retrieving the next user command. 
   
   
     5. The method for managing power consumption by the handheld measurement system according to  claim 1 , further comprising: determining if a user inactivity timeout period has expired when no sled sensor command has been received from the user by the handheld computer and if the user inactivity timeout period has expired sending a sensor power-off command to the one or more sensors and retrieving the next user command. 
   
   
     6. The method for managing power consumption by the handheld measurement system according to  claim 1 , further comprising: determining if a sensor warm-up period is required to the command sent from the handheld computer which turns on one or more sensors and if a sensor warm-up period command has been sent then delaying user input until the sensor warm-up period completes and retrieving the next user command. 
   
   
     7. A method for managing power consumption by a user in a handheld measurement system having a handheld computer connected to a measurement sled and one or more sensors, comprising:
 retrieving user commands by performing timing operations by the handheld computer for determining for shutting down sensor power during a period of user inactivity when no measurements are being acquired, and 
 determining if a sensor warm-up period is required to the command sent from the handheld computer which turns on one or more sensors and if a sensor warm-up period command has been sent then delaying user input until the sensor warm-up period completes. 
 
   
   
     8. The method for managing power consumption by the handheld measurement system according to  claim 7 , further comprising: performing sensor power on and off commands by the sled in response to user commands. 
   
   
     9. The method for managing power consumption by the handheld measurement system according to  claim 8 , further comprising: determining if no command has been received from the handheld computer placing the sled's central processing unit in a low power mode. 
   
   
     10. The method for managing power consumption by the handheld measurement system according to  claim 9 , further comprising: determining if the command sent from the handheld computer turns on one or more sensors and if a command has been sent then turning-on the one or more sensors and if no command has been sent then turning-off the one or more sensors and placing the sled's central processing unit in a low power mode. 
   
   
     11. The method for managing power consumption by the handheld measurement system according to  claim 7 , further comprising: determining if a user inactivity timeout period has expired and sending a sensor power-off command to the one or more sensors. 
   
   
     12. The method for managing power consumption by the handheld measurement system according to  claim 11 , further comprising: determining if a sled sensor read command has been received when the user inactivity timeout period has not occurred wherein if the sensor read command has been received then refreshing the user inactivity timeout. 
   
   
     13. A system for managing power consumption by a user in a handheld measurement system having a handheld computer connected to a measurement sled and one or more sensors, comprising:
 means for retrieving user commands by performing timing operations by the handheld computer for determining when sensor warm up is required and means for shutting down sensor power during a period of user inactivity when no measurements are being acquired, and 
 means for determining if a command has been sent from the handheld computer to the sled wherein if a command has been sent then turning-on the sled's central processing unit and means for performing the command and if no command has been received placing the sled's central processing unit in a low power mode. 
 
   
   
     14. The system for managing power consumption by the handheld measurement system according to  claim 13 , further comprising: means for performing sensor power on and off commands by the sled in response to user commands. 
   
   
     15. The system for managing power consumption by the handheld measurement system according to  claim 14 , further comprising: means for determining if the command sent from the handheld computer turns on one or more sensors and if a command has been sent then turning-on the one or more sensors and if no command has been sent then turning-off the one or more sensors and means for placing the sled's central processing unit in a low power mode. 
   
   
     16. The system for managing power consumption by the handheld measurement system according to  claim 15 , further comprising: means for determining if a user inactivity timeout period has expired when no sled sensor command has been received from the user by the handheld computer and if the user inactivity timeout period has expired sending a sensor power-off command to the one or more sensors and retrieving the next user command. 
   
   
     17. The system for managing power consumption by the handheld measurement system according to  claim 16 , further comprising: means for determining if a sled sensor read command has been received when the user inactivity timeout period has not occurred wherein if the sensor read command has been received then means for refreshing the user inactivity timeout and retrieving the next user command.